WASHINGTON 
Not a day goes by that Zach Camp doesn't replay that terrible August day over in his mind.

Was there anything he could have done differently? Were there any signs that an Afghan Army soldier was going to turn his machine gun on the American troops he had been training alongside for months?

Nearly three months after the assault that sent Camp home with a gunshot wound, the Army first lieutenant says he doesn't think there was any way he or his fellow team members could have anticipated the insider attack.

But after three surgeries to remove the bullet and fragments from his leg and months of physical therapy, Camp is turning his injury into a teaching tool for other U.S. troops heading to Afghanistan to work with Afghan forces.

"You get overwhelmed with a sense of betrayal, that you just got attacked by the same people you are trying to help," said Camp, who deployed to Afghanistan in April with an Army team assigned to train Afghans in the rugged mountains near the Pakistan border. "I didn't know who it was, I didn't know it was an insider attack. It was hard to tell even where it was coming from - you just didn't think it was coming from the actual place that we were going to."

But it was.

The American team had just stepped outside the gate of U.S. forward operating base Mehtar Lam to make their daily trek across the street to the compound where they would train Afghan troops when they were met with a barrage of machine gun fire. An Afghan Army soldier, who probably had been training with the Americans for some time, shot two U.S. troops - Camp and an unidentified soldier who part of a nearby helicopter crew.

Other U.S. troops quickly came to the team's rescue and killed the Afghan soldier.

At least 43 separate insider attacks, where members of the Afghan security forces or insurgents dressed in their uniforms turn their guns on U.S. and allied troops, have killed more than 60 NATO service members. That includes at least five attacks in the past two weeks.

The assaults have rattled the trust between the NATO and Afghan troops, raising questions about how effectively the allied forces can train the Afghans to take over security of their own country in 2014 and beyond.

In response, the U.S. has bolstered security surrounding its troops in Afghanistan and increased training on how to spot and prevent the deadly attacks, even as more of the training teams prepare to head to the front.

For the first time, the instruction for the teams involves a presentation from someone who's experienced such an attack. Part of Camp's message is that things can change very quickly.

"I think the fact that it's one of their own telling them that, yes, this has happened to me, and it is a very real danger, I think it does hit closer to home with a lot of people versus just having a power point slide saying this is a statistic," Camp said. "I know we see it on the news all the time, I saw it on the on the news just a few days ago, but I think when you have that real person sitting in front of you sharing that experience it become a lot more real."

The training at the Joint Readiness Training Center at Fort Polk, La., and the National Training Center at Fort Irwin, Calif., now includes scenarios modeled after actual insider attacks that have happened over the past year.

Gen. David Rodriguez, head of U.S. Army Forces Command, said analysts go through all the details of the attacks and build training exercises for the soldiers from them.

"So there's nowhere they go in the training center where there is not a training challenge that's like they're facing over there in Afghanistan," Rodriguez said. "We're putting a lot of emphasis on this. And any time we see a different situation over there, we adjust the training."

Some attacks have been linked to Afghans who have gone home, become radicalized and then returned to their unit. So the training reflects that and includes Afghan role players displaying the characteristics of people who have undertaken those types of attacks, Rodriguez said.

Army units going through the training are taught to keep a "relentless focus on building and maintaining rapport with their (Afghan) counterpart," said Col. Matthew McKenna, commander of the 162nd Infantry Brigade, which does much of the training. "So, your Afghan counterpart will let you know if something's wrong. The Afghans are able to track who's coming and going. When you do have that good relationship with them, they will let you know."

Members of the 4th Brigade, 3rd Infantry Division who are at Fort Polk are getting two hours of classroom instruction and then frequent tests and training during exercises meant to replicate likely incidents, he said.

The teams get an eight-day course on security force training and then spend 14 days on exercises out in the training area, which includes mock Afghan towns and facilities. In one exercise an Afghan role player comes into a meeting with allied troops and is hiding a pistol. The team has to be able to screen the Afghans and find the one with the gun.

Camp's presentation offers a more personal message.

He tells them what happened to him, that he was lucky to be close to some security barriers he could crawl behind, and that even as he and a team member started performing first aid, he could hear bullets flying.

He remembers calling for help and that the quick reaction forces came right away. He knows that a medic was there and that when he got into the back of an armored truck, his body armor was pulled off and his wound was stuffed with gauze to stop the bleeding.

Only later, when Camp was in the hospital in Germany, did his team members fill him in with more of the details when they called to check on his injury. He said they all figure it had to be an Afghan they had known for a while because no one new had come in. But to this day, he doesn't know why.

"I'll be honest, I probably play this back in my head every single day, to think what could we have done to avoid this, could anything have been done to avoid it," said Camp. "But I feel like everything that my team and I did, and the training we received was spot on, so I'm not going fault anything that we did out there that day. It's probably just one of those that was unavoidable."